There are more entries about exhaust, link pipes, slip ons, etc. But I have not seen this definitively answered: If I use a link pipe and my original slip on, will the stock map work well?

Exactly I felt the same way trying to find the answer/s
I fitted a Bodis de-cat link pipe & wanted to know if it will run too lean by opening up the exhaust, most people tell you it is fine, some say it would need a re-map, I actually read on another forum that the SD runs rich on our Australian fuel so leaning it out would not hurt (not sure where you are?)

While my SD was getting a service & the re-map done I took a demo SD that had the re-map done & knew straight away it was the right thing to do, so the only thing I can say for sure......after fitting the Bodis link pipe it seemed to run much better by removing the restriction but after the re-map which was only done today it seemed to be a totally different animal
I would seriously recommend getting the Akra re-map done, well worth it, It idles better, accelerates so much better & simply sounds better